List the cross-registry activity feed

{  "items": [    {      "id": "string",      "actor": {        "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",        "handle": "string",        "displayName": "string",        "avatarUrl": "string"      },      "kind": "publish",      "ref": "string",      "registryId": "771eb7a3-9cd7-46d3-86da-9e7e93b08f17",      "detail": "string",      "at": "2019-08-24T14:15:22Z"    }  ],  "nextCursor": "string"}

{  "defined": true,  "code": "UNAUTHORIZED",  "status": 401,  "message": "Authentication required or credentials invalid.",  "data": null}

{  "defined": true,  "code": "NOT_FOUND",  "status": 404,  "message": "The requested resource does not exist.",  "data": {    "resource": "string"  }}

{  "defined": true,  "code": "VALIDATION",  "status": 422,  "message": "The input failed domain validation.",  "data": {    "issues": [      {        "path": "string",        "message": "string"      }    ]  }}

{  "defined": true,  "code": "RATE_LIMITED",  "status": 429,  "message": "Rate limit exceeded; retry later.",  "data": {    "retryAfterSeconds": -9007199254740991  }}